From: iceman1001 <iceman@iuse.se>
Date: Wed, 31 Aug 2016 17:17:39 +0000 (+0200)
Subject: FIX:  Forget that the prng was 0x8000 length and not 0xFFFF.  Sorry.  Also returned... 
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/be818b141745aa0831dba63d2e5f9cd088614c98?ds=sidebyside

FIX:  Forget that the prng was 0x8000 length and not 0xFFFF.  Sorry.  Also returned to the decomposed loop.  Don't know if this armsrc optimises this at compilation time. Does someone know?

CHG: returned the iso14443a_setup order, it might influence my older PM3 device.

*Note*  my Elechouse revisions PM3 works great with this but my older xpfga (green pcb) is hopeless.  It can't fix onto the nonces in 'hf mf mifare'  I think its too slow.
---

diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 88d2b078..26781095 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -1987,31 +1987,29 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u
 }
 
 void iso14443a_setup(uint8_t fpga_minor_mode) {
+
 	FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
 	// Set up the synchronous serial port
 	FpgaSetupSsc();
 	// connect Demodulated Signal to ADC:
 	SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
 
-	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
-	
 	LED_D_OFF();
 	// Signal field is on with the appropriate LED
 	if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD ||
 		fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN)
 		LED_D_ON();
 
-	// Prepare the demodulation functions
-	DemodReset();
-	UartReset();
-
-	iso14a_set_timeout(10*106); // 10ms default
-
-	//NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
-	NextTransferTime = DELAY_ARM2AIR_AS_READER << 1;
+	FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
 	
 	// Start the timer
 	StartCountSspClk();
+	
+	// Prepare the demodulation functions
+	DemodReset();
+	UartReset();
+	NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
+	iso14a_set_timeout(10*106); // 10ms default	
 }
 
 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
@@ -2044,6 +2042,7 @@ int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
 	return len;
 }
 
+
 //-----------------------------------------------------------------------------
 // Read an ISO 14443a tag. Send out commands and store answers.
 //
@@ -2145,10 +2144,31 @@ int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
 	uint32_t nttmp1 = nt1;
 	uint32_t nttmp2 = nt2;
 
-	for (uint16_t i = 1; i < 0xFFFF; ++i) {
+	for (uint16_t i = 1; i < 32768/8; ++i) {
 		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i;
 		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -i;
-	}	
+		
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+1;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+1);
+		
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+2;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+2);
+
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+3;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+3);
+		
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+4;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+4);
+		
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+5;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+5);
+		
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+6;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+6);
+		
+		nttmp1 = prng_successor(nttmp1, 1);	if (nttmp1 == nt2) return i+7;
+		nttmp2 = prng_successor(nttmp2, 1);	if (nttmp2 == nt1) return -(i+7);		
+	}
 	// either nt1 or nt2 are invalid nonces	
 	return(-99999); 
 }